Retirement Withdrawal Calculator
Determine how much your retirement portfolio can sustainably provide each year, accounting for investment returns and inflation. Use this when planning income distributions from a 401(k), IRA, or other retirement savings.
About this calculator
This calculator estimates the real present value of your first-year withdrawal amount, discounted back from the end of your retirement to reflect how purchasing power changes over time. The formula is: Adjusted Withdrawal = portfolioValue × (withdrawalRate / 100) / (1 + (expectedReturn − inflationRate) / 100)^retirementLength. The numerator calculates the raw annual withdrawal in today's dollars. The denominator discounts that figure by the real return — expected portfolio return minus inflation — compounded over the full retirement duration. This captures the insight that a dollar withdrawn in year 30 of retirement is worth far less in real terms than one withdrawn today. The widely cited 4% rule (a 4% withdrawal rate on a 30-year horizon) derives from historical simulations showing this level rarely depletes a diversified portfolio.
How to use
Assume a $1,000,000 portfolio, a 4% withdrawal rate, 6% expected return, 2.5% inflation, and a 30-year retirement. Step 1 — raw annual withdrawal: $1,000,000 × 4/100 = $40,000. Step 2 — real return rate: 6 − 2.5 = 3.5%. Step 3 — discount factor: (1 + 0.035)^30 = 2.8068. Step 4 — adjusted withdrawal: $40,000 / 2.8068 = $14,251. This tells you that $40,000 withdrawn annually has a real present value of about $14,251 per year when adjusted for 30 years of inflation and portfolio growth.
Frequently asked questions
What is the 4% rule for retirement withdrawals and is it still valid?
The 4% rule originated from William Bengen's 1994 research showing that a retiree could withdraw 4% of their portfolio in year one, adjust for inflation annually, and not run out of money over a 30-year retirement based on historical US market data. Its continued validity is debated today because the rule was derived from a specific historical period of relatively high bond yields and equity returns. With current low yields and elevated valuations, some financial planners suggest 3–3.5% as a more conservative safe withdrawal rate. The rule remains a useful starting benchmark but should be revisited regularly.
How does inflation affect retirement portfolio longevity?
Inflation erodes the purchasing power of every dollar withdrawn, meaning retirees must either withdraw larger nominal amounts each year or accept a lower standard of living. A 3% annual inflation rate roughly halves purchasing power over 24 years, which is significant for a 30-year retirement. Higher inflation also pressures bonds and cash equivalents, which are common in retirement portfolios, reducing real returns. This calculator incorporates inflation by using the real return (expected return minus inflation rate) in the discounting formula.
What expected portfolio return should I use for retirement planning?
A conservative and widely used assumption for a balanced retirement portfolio (e.g., 50–60% equities, 40–50% bonds) is a nominal annual return of 5–7%. More aggressive equity-heavy portfolios might assume 7–8%, while income-focused portfolios might use 4–5%. It is prudent to stress-test your plan with lower return assumptions — say 4% — to confirm your savings last even in a below-average market environment. Financial planners often use Monte Carlo simulations to model the range of possible outcomes rather than relying on a single return estimate.